import matplotlib.pyplot as plt
import numpy as np

x=np.linspace(-3,3,50)
y1=2**x
plt.figure(num=3,figsize=(8,5))
plt.plot(x,y1,color='red',linewidth=5)
plt.yticks([-3,-1,0,1,3],["bad","normal","good","very good","super"])
ax=plt.gca()
ax.spines["top"].set_color("none")

plt.legend(['country'])
# 数据降维

plt.show()